Texture Morphology Research Articles

A novel higher order appearance texture analysis to diagnose lung cancer based on a modified local ternary pattern

Background and ObjectiveLung cancer is an important cause of death and morbidity around the world. Two of the primary computed tomography (CT) imaging markers that can be used to differentiate malignant and benign lung nodules are the inhomogeneity of the nodules’ texture and nodular morphology. The objective of this paper is to present a new model that can capture the inhomogeneity of the detected lung nodules as well as their morphology. MethodsWe modified the local ternary pattern to use three different levels (instead of two) and a new pattern identification algorithm to capture the nodule’s inhomogeneity and morphology in a more accurate and flexible way. This modification aims to address the wide Hounsfield unit value range of the detected nodules which decreases the ability of the traditional local binary/ternary pattern to accurately classify nodules’ inhomogeneity. The cut-off values defining these three levels of the novel technique are estimated empirically from the training data. Subsequently, the extracted imaging markers are fed to a hyper-tuned stacked generalization-based classification architecture to classify the nodules as malignant or benign. The proposed system was evaluated on in vivo datasets of 679 CT scans (364 malignant nodules and 315 benign nodules) from the benchmark Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI) and an external dataset of 100 CT scans (50 malignant and 50 benign). The performance of the classifier was quantitatively assessed using a Leave-one-out cross-validation approach and externally validated using the unseen external dataset based on sensitivity, specificity, and accuracy. ResultsThe overall accuracy of the system is 96.17% with 97.14% sensitivity and 95.33% specificity. The area under the receiver-operating characteristic curve was 0.98, which highlights the robustness of the system. Using the unseen external dataset for validating the system led to consistent results showing the generalization abilities of the proposed approach. Moreover, applying the original local binary/ternary pattern or using other classification structures achieved inferior performance when compared against the proposed approach. ConclusionsThese experimental results demonstrate the feasibility of the proposed model as a novel tool to assist physicians and radiologists for lung nodules’ early assessment based on the new comprehensive imaging markers.

Sponge-like nanoporous activated carbon from corn husk as a sustainable and highly stable supercapacitor electrode for energy storage

Corn husk, an abundant agro-industrial waste was employed to produce activated carbon for energy storage. The sponge-like activated carbons were produced with environmentally friendly potassium carbonate (K2CO3) at different impregnation ratio (corn husk:K2CO3; 1:1 to 1:3) and activation temperatures (500–800 °C). The obtained activated carbon was used to produce electrodes for supercapacitor application. The results revealed that corn husk: K2CO3 ratio of 1:2 and 650 °C promoted mainly nanopores (0.773 nm) with appreciably higher specific surface area (1115 m2/g) and a sponge morphology. The electrochemistry performance test on the materials shows specific capacitances of up to 269 F/g at 5 mV/s scan rate for a material obtained at 650 °C. The textural characteristics, morphology, and heteroatoms of sulfur and nitrogen significantly promoted higher energy storage capacity. This activated carbon was employed to assemble a symmetric supercapacitor in acidic electrolyte (0.5 M H2SO4) that delivered up to ~10 Wh/kg and was very stable, maintaining about 99.5 % of its original energy after 20,000 charge/discharge cycles.

Three-dimensional recyclable FeS2/reduced graphene oxide aerogel with high porosity reticulated structure for efficient removal of tylosin tartrate

FeS2 has been applied in photocatalysis for removing organic pollutants in view of waste treatment by waste. However, powdered FeS2 still faces challenges such as easy recombination of photogenerated charges, susceptibility to corrosion, and difficulty in recycling. In this study, a three-dimensional FeS2/reduced graphene oxide aerogel (3D FeS2/rGOA) composite was synthesized through a self-assembly hydrothermal method to degrade the antibiotic tylosin tartrate. FeS2 was encapsulated by rGO and formed chemical bonds with it, creating a stable three-dimensional reticulated structure with well mechanical property, porous morphology and lightweight texture. The results showed that the FeS2/rGOA significantly improved the removal of tylosin tartrate, achieving 92.5%. The rGOA enhanced FeS2’s adsorption performance and narrowed the band gap of the composite, which improved its light absorption capacity. The reticulated structure of the rGOA facilitated electron transfer and extended the lifetime of photogenerated carriers. Moreover, the electron transfer channels in rGO resulted in electrons with longer lifetimes participating in reactions that generated free radicals. Additionally, it benefited to oxygen acting as an electron acceptor to produce hydrogen peroxide under acidic conditions regulated by FeS2, which is conducive to Fenton reaction. As a result, free radical quenching experiments and EPR tests showed that h+, ·O2–, ·SO4-, and ·OH were effective active species during the photocatalytic process. Furthermore, the stable chemical bonds between FeS2 and rGOA inhibited corrosion of FeS2. The three-dimensional structure of the composite with well mechanical property made it easy to recycle. The high stability and ease of recovery ensured the reuse of the FeS2/rGOA composite. The plausible degradation path of TYL was proposed based on the LC-MS results. This work provides a strategy for making FeS2 recoverable and highly catalytic for the degradation of antibiotics.

High-resolution Bragg-edge neutron radiography detects grain morphology in PBF-LB/M IN718

One of the main advantages of metal additive manufacturing (MAM) techniques is their ability to produce components with site-specific microstructural features. Nevertheless, microstructural defects and lack of repeatability are still major concerns in MAM. In this study, a laser powder bed fusion (PBF-LB/M) IN718 material, produced using two different scan length vectors, is investigated using Bragg-edge neutron 2D imaging (BENI) combined with electron backscatter diffraction (EBSD) analysis. BENI is able to detect, on a macroscopic scale, process-induced changes in texture in a large field of view covering the entire sample (20×80 mm2). In addition, high-resolution BENI (HR-BENI), with a pixel size of 12.8 µm, provides a micro-scale examination of the local variations of texture and grain morphology, otherwise undistinguishable using the standard resolution. As such, HR-BENI offers a straightforward and detailed way of screening the integrity of MAM parts at cm-length scales.

Facile and green synthesis of disordered mesoporous silica as biogenic filler for mixed-matrix membranes

Disordered mesoporous silica particles (MSNs) were successfully synthesized using facile sol-gel using rice husk as a silica precursor and water-soluble polymers as structure-directing agents (SDAs) under acidic conditions of gluconic acid solutions. The influence of polyvinyl alcohol/PVA, polyvinylpyrrolidone/PVP, and soluble starch on the textural properties and morphologies were studied. Besides, the impact of MSNs with considerable properties on the CO2/N2 separation performance of poly(ether-block-amide) or Pebax membranes was also investigated. SDAs could generally double the specific surface area of the original sample up to 400–600 m2/g, except PVP/starch and PVA/PVP. In addition, PVP governed spherical shape, while its combination with PVA established excellent particle size distribution (100–200 nm). MSNs prepared using PVA/PVP were even considered to upgrade Pebax membrane's CO2/N2 separation performance. CO2 permeability and CO2/N2 selectivity were enhanced up to 58% and 21%, respectively, compared to pure Pebax membranes. This finding will be promising for encouraging sustainable filler development for membrane technology.

Second harmonic generation on crystalline organic nanoclusters under extreme nanoconfinement in functionalized silica–benzil composites

We demonstrate a series of organic–inorganic nanocomposite materials combining the mesoporous silica (PS) and benzil (BZL) nanocrystals embedded into its nanochannels (6.0–13.0 nm in diameter) by capillary crystallization. One aims to design novel, efficient nonlinear optical composite materials in which inactive amorphous host PS-matrix provides a tubular scaffold structure, whereas nonlinear optical functionality results from specific properties of the deposited guest BZL-nanocrystals. A considerable contraction of the BZL melt during its crystallization inside the silica nanochannels results in a formation of the texture consisting of (221)- and (003)-oriented BZL nanoclusters (22 nm in length), separated by voids. Specificity of the textural morphology similarly to the spatial confinement significantly influences the nonlinear optical features of composite PS:BZL materials being explored in the second harmonic generation (SHG) experiment. The light polarization anisotropy of the SHG response appears to be considerably reduced at channel diameters larger than 7 nm apparently due to the multiple scattering and depolarization of the light on randomly distributed and crystallographically oriented BZL-nanoclusters. The normalized SHG response decreases nonlinearly by more than one order of magnitude as the channel diameter decreases from 13.0 to 6.0 nm and vanishes when spatial cylindrical confinement approaches the sizes of a few molecular layers suggesting that the embedded BZL clusters indeed are not uniformly crystalline but are characterized by more complex morphology consisting of a disordered SHG-inactive amorphous shell, covering the channel wall, and SHG-active crystalline core. Understanding and controlling of the textural morphology in inorganic–organic nanocrystalline composites as well as its relationships with nonlinear optical properties can lead to the development of novel efficient nonlinear optical materials for the light energy conversion with prospective optoelectronic and photonic applications.

The effect of the redox potential of annealing environment on the mechanical properties of Al2O3-YAG:Ce eutectics

Mechanical characteristics of the eutectics Al2O3-Y3Al5O12:Ce grown by the method of horizontal directional crystallization were established. The influence of the redox potential of the annealing environments on the microhardness and fracture toughness of Al2O3-Y3Al5O12:Ce eutectics has been investigated. Three kinds of environments that differed by the redox potentials have been applied: oxidizing (in the air), in a vacuum, and reducing (Ar. CO, H2).The obtained results showed that doping with Ce ions deteriorates the mechanical properties of the Al2O3-YAG eutectic, both microhardness and fracture toughness. Annealing improves the mechanical properties of the eutectic for all concentrations of Ce ions, but the value of the redox potential of the annealing environment does not affect the degree of the enhancement of these mechanical properties. Only vacuum annealing has a stronger effect on the fracture toughness of eutectics. The increase in microhardness in samples with Ce after annealing is more noticeable compared to samples without Ce.Despite the anisotropy of the eutectic morphology and crystalline texture of the constitutional phases, the mechanical properties of the eutectics didn’t depend noticeably on the direction in the ingot.

Environment‐friendly g‐C3N4/SnO2/BiPO4 for enhanced Rhodamine B photocatalysis under visible‐light

AbstractObjectiveA highly active and stable composite photocatalyst which can be used in practical environmental remediation was developed.Methodsg‐C3N4/SnO2/BiPO4 ternary composites (CN/SO/BPO) were synthesised via simple impregnation, and their texture structure, morphology, and surface composition were deeply characterized.ResultsIn just 25 min under visible‐light radiation, CN/SO/BPO almost eliminated rhodamine B, and the observed rate constant for the reaction was almost 36 and 3 times higher in comparison to that of CN/BPO and SO/BPO, respectively.ConclusionsOn the basis of experimental outcomes and DFT calculation, the direct Z‐type structure of CN/SO/BPO lead to the improved photogenerated charge separation efficiency, as confirmed by surface photovoltage spectroscopy, electrochemical impedance spectroscopy, and transient photocurrent responses.

Comparison of hydrophilic and hydrophobic nano topographic surfaces of titanium alloys on pre-osteoblastic cell interaction

This work aimed to assess the influence of different structured substrates with hydrophilic and hydrophobic properties on micro and nano topographies developed on titanium alloys over pre-osteoblastic cell behavior. Nano topography influences small dimension levels of cell morphology by inducing filopodia formation in cell membranes, irrespectively to the wettability behavior of the surface. Therefore, micro and nanostructured surfaces of titanium-based samples using different techniques of surface modification processing, such as chemical treatments, micro-arc anodic oxidation (MAO), and MAO combined to laser irradiation were developed. Isotropic and anisotropic texture morphologies, wettability, topological parameters and compositional alterations were measured after the surface treatments. Finally, cell viability, adhesion and morphological responses were assessed to investigate the influence of distinct topologies on osteoblastic cells aiming to encounter the conditions to better promote mineralization events. Our study demonstrated that the hydrophilic behavior improves cell adhesion, amplified when effective surface area increases. Surfaces presenting nano topography have a direct influence on cell morphology and play a key role for filopodia formation.

Skin Lesions Detection using Deep Learning Techniques

Abstract: The main category of cancer is skin cancer, which is manifested by certain skin diseases. They have been constrained into various typologies stationed on morphological features, color, structure, and texture. Due to certain factors, the study equips analysis efforts to advance algorithms with greater closeness and tensility in detecting early-stage melanoma. As per the ACS report, melanoma is one of the recurrent cancers in the world. In 2017, around 87,110 new cases were diagnosed in the United States alone. Dermoscope images contain imperfections such as shadows, artifacts, and noise that degrade image essence. To overthrow these objection, deep learning neural networks have been used to detect skin cancer by tampering images. In the proposed work, automatic classification of skin lesions is proposed. Image classification, object detection etc are some of the computer vision tasks in deep CNN which have driven DCNNs to be reliable on several substitute assumptions, tiling its way for new exploration areas. CNN attained performance equivalent to all experts tested, achieving an exact competence equivalent to dermatologists treating skin cancer. In this article, we attempt to improve the Deep Convolutional Neural Networks example using the ImageNet dataset with HAM10000, fortuitously classifying seven categories of skin lesions. HAM10000 is a dataset of 10000 dermoscope images. Layers are fine-tuned applying separate approach such as InceptionV3, InceptionResNet, DenseNet and VGG-16. Over previous years, the power of deep learning-based approaches has enhanced fiercely and their work come out to outperform common image processing approach on classification tasks. However, these categories of machine learning-based accession have important drawbacks. Training requires thousands of annotated images for each class. The idea is to use deep learning algorithms and available dataset assets to bear models with higher accuracy and best results.

Copper-based halide films with high photoluminescence quantum yield in the visible region deposited in situ by double source aerosol-assisted chemical vapor deposition

A huge family of luminescent low-dimensional metal halides for optoelectronic applications has emerged recently as a green alternative to the highly toxic lead halide phosphors. To date, studies on the controlled deposition of these materials as films to be integrated into optoelectronic architectures remain scarce. Here, the synthesis and characterization of highly luminescent films of copper halide phosphors with emissions in violet: K2CuCl3, blue: Cs5Cu3Cl6I2, and green: Cs3Cu2Cl5 are reported. The films were obtained by multisource aerosol-assisted chemical vapor deposition (AACVD) from methanolic solutions at low temperature and under ambient conditions. Photoluminescent quantum yield values obtained for the films deposited on quartz substrates have values of 52% for K2CuCl3, 85% for Cs5Cu3Cl6I2, and 99% for Cs3Cu2Cl5. These values were highly influenced by the substrate since for samples deposited on glass substrates the values are 26.17% for K2CuCl3, 60.47% for Cs5Cu3Cl6I2, and 59.7% for Cs3Cu2Cl5. Different textured morphologies, with valuable applications in light-harvesting, were found for each stoichiometry. Finally, x-ray photo-emitted spectroscopy was employed to demonstrate the existence of only Cu(I) highly emissive species, suggesting that AACVD could be an excellent alternative for metal halide film deposition.

Coupling effects of SiC and TiB2 particles on crack inhibition in Al-Zn-Mg-Cu alloy produced by laser powder bed fusion

A novel Al-Zn-Mg-Cu alloy free of cracks was produced utilizing laser powder bed fusion (LPBF) and modified with SiC and TiB2 particles. The interdependent effects of SiC and TiB2 particles on morphology, microstructure, and crystallographic texture were examined. The mechanisms behind phase evolution and crack inhibition were elucidated. The results show that a nearly dense Al-Zn-Mg-Cu alloy could be obtained when the mass fraction of SiC and TiB2 particles was 4%. TiB2 particles remained stable and acted as nucleation agents in the molten pool. Partial SiC particles reacted with the Al matrix to form rod-like Al4C3, lamellate Al4SiC4, and flocculent Si phases, which provided nucleation agents and liquid replenishment for matrix grains. The columnar grains of the matrix were refined into equiaxed grains, and the average size decreased from 37.15 μm to 7.54 μm. The preferential growth of grains along the (001) 〈001〉 direction was suppressed and transformed into a disordered random growth. The innovative Al-Zn-Mg-Cu alloy demonstrated an ultimate tensile strength of 492±12 MPa and an elongation of 7.2%±0.7%. The microhardness was enhanced, and the microhardness heterogeneity was reduced. The solidification properties were regulated, the temperature interval between solidus and liquidus was narrowed, and the liquidity of the molten pool was improved. The hot cracking of Al-Zn-Mg-Cu alloy was inhibited due to the interdependent effects of grain refinement by TiB2 particles and sufficient liquid metal replenishment by SiC particles.

Probing the atomically diffuse interfaces in Pd@Pt core-shell nanoparticles in three dimensions

Deciphering the three-dimensional atomic structure of solid-solid interfaces in core-shell nanomaterials is the key to understand their catalytical, optical and electronic properties. Here, we probe the three-dimensional atomic structures of palladium-platinum core-shell nanoparticles at the single-atom level using atomic resolution electron tomography. We quantify the rich structural variety of core-shell nanoparticles with heteroepitaxy in 3D at atomic resolution. Instead of forming an atomically-sharp boundary, the core-shell interface is found to be atomically diffuse with an average thickness of 4.2 Å, irrespective of the particle’s morphology or crystallographic texture. The high concentration of Pd in the diffusive interface is highly related to the free Pd atoms dissolved from the Pd seeds, which is confirmed by atomic images of Pd and Pt single atoms and sub-nanometer clusters using cryogenic electron microscopy. These results advance our understanding of core-shell structures at the fundamental level, providing potential strategies into precise nanomaterial manipulation and chemical property regulation.

A Single-Step Route to Robust and Fluorine-Free Superhydrophobic Coatings via Aerosol-Assisted Chemical Vapor Deposition.

Robust fluorine-free superhydrophobic films were produced from a mixture of two fatty acids (stearic acid and palmitic acid), SiO2 nanoparticles, and polydimethylsiloxane. These simple and nontoxic compounds were deposited via aerosol-assisted chemical vapor deposition to provide the rough topography required for superhydrophobicity, formed through island growth of the aggregates. The optimum conditions for well-adhered superhydrophobic films produced films with a highly textured morphology, which possessed a water contact angle of 162 ± 2° and a sliding angle of <5°. Superhydrophobicity was maintained after ultraviolet exposure (14 days at 365 nm), heat treatment (5 h at 300 °C and 5 h at 400 °C), 300 tape peel cycles, and exposure to ethanol and toluene (5 h each).

Experimental Study on the Wear Characteristics of Textured Joint Surfaces under Bionic Lubrication

Ti15Mo7Zr15Ta1.00Si titanium alloy contained higher concentration of silicon and better elastic properties, excellent biocompatibility and lower processing cost. To investigate the influence of texture shapes and parameters of joint surfaces on the friction and wear properties under bionic lubrication conditions, three types of texture morphologies (circular, elliptical, and equal-width grating) with the same pit depth and surface coating rate were processed on a Ti15Mo7Zr15Ta1.00Si titanium alloy using a picosecond laser processing system in this study. Then, the "ceramic–metal" friction and wear tests of textured and smooth samples under lubrication with bovine serum protein were performed using a UMT-3 multifunctional friction and wear testing machine. The results showed that the surface micro-texture morphology could improve the anti-friction properties of titanium alloy artificial joint materials. The wear resistance of the circular micro-dimples improved with an increase in the circular diameter. In the elliptical micro-dimple texture morphology, the vertical arrangement of the ellipses could provide the maximum bearing capacity and best friction reduction effect, followed by the elliptical morphology and the transverse ellipse arrangement. The denser the arrangement of the equal-width bars, the better the friction reduction effect was.

Structural characters of biaxially stretched polypropylene films and the relevant electrical insulating properties

Abstract Capacitor films from biaxially oriented polypropylene (BOPP) involve intensive external stress field, resulting in special crystallization and orientation characters. However, it still remains ambiguous on the relationship between crystallized morphology in BOPP bulk film and electric properties. In this work, two stretching modes, simultaneously biaxial stretching and sequentially biaxial stretching, were chosen to adjust film thickness, extended chain crystal content, fibrillar morphology, and orientation texture. Meanwhile, the working rules of these structural issues on electrical insulating properties were inspected. It reveals that extended chain crystals with thermal stability and isotropous fibrillated network favor to improved breakdown strength and lowered dielectric loss. These results offer good understanding on the processing-structure-property relation of polymer film dielectrics.

Optical Design Impact on PERC Solar Cell Efficiency: Upright Pyramids vs Inverted Pyramids Textured Surfaces

Aims: Textured surfaces morphology on solar cell are benefited to minimize the reflection. Many configurations are used for solar cell manufacturing. The ray’s simulators are used in this work. The gains (photogeneration) and losses (reflection, transmission, parasitic absorption) are recorded for each ray. The global gains and losses are determined by averaging many rays. With a sufficiently large number of rays, the Monte Carlo simulation converges to the physical model. The Monte-Carlo algorithm employed by the Wafer Optics Calculator necessarily results in output uncertainties. These uncertainties are calculated by dividing the user-requested number of rays into several sub-simulations, then applying statistical analysis to the set of sub-simulations to arrive at a mean value and 95% confidence interval (about two standard deviations). The calculators weight the magnitudes by the photon flux in the user-defined spectrum, then integrates over the wavelength, to calculate photon current density. The photogenerated current JG in a wafer equates to the short circuit current that could be extracted from a perfect solar cell made from the wafer. This work focuses on two textured surfaces morphology such that, upright pyramids, and inverted pyramids. To show their impact in solar cell efficiency. Which involve evaluating the external reflection for both surface morphology. Also compare the photogeneration JG absorbed by the substrate.

Inception of macroscopic shear bands during hot working of aluminum alloys

Macroscopic shear bands (MSB) may develop during hot working of metallic materials. They are well-understood as a physical manifestation of flow instability, and the processing regimes wherein they form are well-charted. However, the microstructural transitions that occur between the onset of flow instability and MSB inception are not fully understood. In order to elucidate them, several aluminum alloy specimens were subjected to strip testing in a thermomechanical simulator (Gleeble™) at 298 K and 573 K. Prominent MSB were observed along the diagonals of the strip volume of only Aluminum-6 wt% Magnesium alloy specimen deformed at 573 K. Comparing the experimental grain morphology and crystallographic textures with those from plastic flow models revealed that MSB inception occurred only after ∼0.20 homogeneous plane strain deformation. However, classical flow instability was predicted at much smaller strain. This ‘delay’ was explained experimentally by showing that clusters of neighbouring severely deforming, fragmenting, mostly soft-oriented grains gradually developed due to lattice rotations along the specimen diagonals, and that MSB inception corresponded to the formation of a percolating network of such grains spanning the specimen. Further, clear experimental evidence revealed that differential dynamic recovery between hard- and soft-oriented grains was essential for MSB formation.

A paleoplacer component to the gold hosted in meta-conglomeratic units of the Neoarchaean moto greenstone belt, DRC

The giant Karagba-Chauffeur-Durba (KCD) gold deposit and its peripheral gold satellite deposits are located within the Kibali gold district in the Neoarchaean Moto Greenstone Belt in the northeast of the Congo Craton, Democratic Republic of Congo. The gold mineralisation within the KCD area occurs within altered chemical sedimentary rocks such as banded iron formation (BIF) and chert, as well as in meta-carbonaceous argillite, meta-sandstones and poorly-sorted pebble meta-conglomerates. To elucidate and characterise the controls on gold mineralisation in the siliciclastic rocks of this sedimentary sequence dating from approximately 2630 to 2625 Ma, the present study critically considers an extensive data set comprising borehole logs, petrographic observations, gold assay data, and mineral chemistry. Detailed high magnification petrographic analyses of polished sections enabled evaluation of 3824 gold grains from meta-conglomerate and siliciclastic sedimentary host rock specimens. These were compared to an additional 985 gold grains from deformed quartz-carbonate (ACSA) altered rocks and BIF host rock types, representing end-members for a purely hydrothermal style of gold mineralisation. These analyses revealed that most of the gold grains in the meta-conglomerates occur within the gangue mineral assemblage in the form of free gold generally distal to any sulphide minerals, with a second population associated with the sulphides, mainly pyrite, followed by arsenopyrite and lesser pyrrhotite. The gold grains in the meta-conglomerates show larger average sizes (433 µm2) than in the grains in the ACSA (311 µm2) and BIF (180 µm2) host rock types. A large dataset of assayed gold results of 9,632,470 data from 3953 drill holes highlights that the ACSA-altered rocks and the chemical sedimentary rocks (chert and BIF) are the main hosts for gold, showing average grades of 3.9, 2.5 and 2.4 g/t when a 0.5 g/t cut-off is applied, respectively. Conversely, meta-conglomerates have a relatively low Au content (1.84 g/t), yet this dataset has an extensive set of outlying values, with 86 data points reflecting grades over 100 g/t. Scanning Electron Microscope (SEM-EDS/WDS) performed on 397 gold grains from meta-conglomerates and deformed quartz-carbonate (ACSA) altered rocks shows mainly Au-Ag alloys, dominated by native gold with averages of 85.46 wt% of Au and 9.76 wt% of Ag in the meta-conglomerates and 86.56 wt% of Au and 12.84 wt% of Ag within the ACSA. Minor amounts of Au-Ag alloys electrum and Au-Hg-Ag alloys amalgams are present predominantly at Gorumbwa and KCD deposits. Our analysis of textural features, mineral chemistry, morphology, assay results, and mineral associations suggests that there are significant differences between the purely hydrothermal mineralisation and the mineralisation hosted by the meta-conglomeratic units. We suggest that the pre-enrichment of these meta-conglomerates by placer processes has played a role in enhancing the fertility for gold mineralisation in the KCD area. This has far-reaching implications for the existing ore-genesis models and exploration paradigms employed in the KCD area. This work presents new opportunities for exploration by highlighting the significance of understanding the stratigraphy and identifying sub-basins that may have undergone early placer enrichments. To achieve this, the early sedimentary environment should be thoroughly investigated.

Application of optical microscopy techniques for the evaluation of raw materials for cement and concrete

Optical microscopy techniques play a prominent role in evaluation of Raw Materials for manufacture of cement and concrete. The present study mainly deals for the evaluation of cement clinker for its development of clinker phases, distribution of all the mineral phases, effect of cooling on clinker microstructure and also grindability of clinker which are helpful in determination of quality of clinker. A detailed study has also been carried out for limestone for its suitability for manufacture of cement and coarse aggregates using optical microscopy techniques for their suitability for concrete making. Studies have also been done for determination of glass content in blast furnace slag for its suitability for manufacture of Portland slag cement which is very good for marine constructions and the constructions in coastal areas. Based on the morphological features, different shapes, grain sizes and textures of clinker, limestone and coarse aggregates the results and conclusions have been arrived and the results provided have been implemented for the quality improvement.